Abaixo está uma instrução que descreve uma tarefa de geração de SQL, combinada com uma entrada que fornece mais contexto sobre os esquemas de tabela disponíveis. Escreva o código SQL que responda adequadamente à solicitação
 ###Instrução: Quando foi a taxa para jovens de 16 a 17 anos de £3.40?
 ###Tabelas: CREATE TABLE starstruck_standing (starstruck_standing_id AUTO_INCREMENT PRIMARY KEY, Week # INT, Finalists VARCHAR, Status VARCHAR, Eliminated VARCHAR, Date VARCHAR) CREATE TABLE current_and_past_rates (current_and_past_rates_id AUTO_INCREMENT PRIMARY KEY, From VARCHAR, Adult Rate VARCHAR, Development Rate VARCHAR, 16-17 Year Olds Rate VARCHAR, Apprentice Rate VARCHAR) CREATE TABLE comparison_chart (comparison_chart_id AUTO_INCREMENT PRIMARY KEY, Project VARCHAR, License VARCHAR, Date VARCHAR, Protocol VARCHAR, Technology VARCHAR, Server VARCHAR, Client VARCHAR, Web Client VARCHAR, Multiple Sessions VARCHAR, Encryption VARCHAR, Authentication VARCHAR, Data Compression VARCHAR, Image Quality VARCHAR, Color Quality VARCHAR, File Transfer VARCHAR, Clipboard Transfer VARCHAR, Chat VARCHAR, Relay VARCHAR, HTTP Tunnel VARCHAR, Proxy VARCHAR) CREATE TABLE western_conference_semi-finals (western_conference_semi-finals_id AUTO_INCREMENT PRIMARY KEY, Date VARCHAR, Visitor VARCHAR, Score VARCHAR, Home VARCHAR, Decision VARCHAR, Attendance INT) CREATE TABLE district_administration (district_administration_id AUTO_INCREMENT PRIMARY KEY, Year VARCHAR, Superintendent VARCHAR, Glendale Principal VARCHAR, H.H. Principal VARCHAR, Maplemere Principal VARCHAR, W.R. Principal VARCHAR, M.S. Principal VARCHAR, H.S. Principal VARCHAR, H. S. Asst. Principal VARCHAR)  
SELECT From FROM current_and_past_rates WHERE 16-17 Year Olds Rate = £3.40